This invention relates to a vehicle wheel suspension, and particularly to an annular elastomeric pad for seating the lower end of a coil spring that surrounds a shock absorber strut for the wheel suspension.
Wheel suspensions of interest are shown in U.S. Pat. No. 4,721,325 to J. Mackovjak, U.S. Pat. No. 5,454,585 to G. Dronen et.al., and U.S. Pat. No. 5,676,355 to N. Hayashi.
The vehicle suspension of particular interest comprises a shock absorber strut that includes an upstanding fluid cylinder having a piston rod connected to the vehicle body and a shock absorbing cylinder connected to the vehicle wheel suspension arm. The vehicle suspension further includes an upper spring seat and strut mount assembly attached to the piston rod and a lower spring seat attached to the shock absorbing cylinder. A coil spring is trained between the two spring seats in surrounding relation to the shock absorber strut. The axis of the spring is offset from the axis of the shock absorber strut.
The present invention relates to the construction of the lower spring seat isolator, whereby the isolator material is resiliently deformable while at the same time being formed of a reasonably high durometer material. The seat structure is thus resistant to failure from the forces imposed thereon by the cyclic compression and relaxation of the spring.
In a preferred practice of the invention the lower spring seat isolator has an annular spring seat surface formed with an array of evenly spaced slot-like depressions spaced around the seat circumference. The depressions form raised ribs on the spring seat that can deform radially, vertically, and circumferentially under spring load forces, even when the seat is formed of a relatively high durometer elastomeric material.
Further features of the invention will be apparent from the attached drawings and description of an illustrative embodiment of the invention.